Fluid-fuel furnace



March 27, 1928.` 1,663,713

H. v; I EAHY FLUID FUEL FURNACE rjiled Nv. e. 192:5 5 sheetspsheet 1 Rg. j

A TTORNEYS March 27, 1928.

H. V. LEAHY FLUID FUEL FURNACE FiledNov. s sheetsQsneet 4 F72 o Q@ o @/v@ ATTORNEYS Patented Mar. 27, 1928.

UNITED, As'ra'rlazs PATENT UFFIC;

FLUID-FUEL FURNACE.

Application mea Nbvember 6, 192s. serial No. 673,222.

My invention relates to fluid fuel furnaces, A

and more particularly, although not necessarily, to oil and gas furnaces.

A purpose of my invention is the provision A -tion the furnace shown in the preceding 6 of a furnace having both oil and gas burners, and means for controlling the supply of fuel thereto in such manner that the oil and gas burners can be used together or separately andthe burners of either type 10 of fuel regulated by `means, common to all of the burners of that type or by individual controls whereby the degree of heat generated andthe distribution of such heat in the furnace can be arbitrarily controlled. 1.5 It is also a purpose of my invention to provide a furnace which, in addition to having the desirable characteristics of structural simplicity and durability, provides a combusti'on chamber surrounded by an air cham- 20 ber through which air circulates and bey`\,eo1 nes preheated before reaching the combiistion chamber so as topromote perfect combustion and prevents loss of heat by radiation.

A further purpose of my invention is the provision of a furnace structure having openings through which cool air is 'supplied to the air chamber, and dampers controlling the openings to provide a positive control 3() chamber..

Further, my invention provides usual accessibility to the burners for cleaning purposes, and the removability of the fire-brick for purposes of substitution.

' I will describe one form of Huid fuel furnace embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings:

-Figure 1 is a view showin@` in vertical section a conventional water tube boiler having applied thereto one form of fluid fuel furnace embodying my invention, the latter being shown somewhat diagrammatically;

Figure 2 is a horizontal sectional View taken on the line 2- -2 of Figure 1;

Figure 2a -is a view similar to Figure 2,l

showing another arrangement of burners embodying my invention;

Figure 3 is a view showing in front elevation the furnace shown in Figures 1 and 2; i Figure 4 is a vertical sectional view taken on the line 44-of Figure 3; s

Figure 5 s a sectional view taken on the line 5-5 of Figure 12; y

of the air admitted to the combustionv Figures 6 and 7 are sectional views taken on the lines 6-6 and`7-7, respectively, of Figures 3 and 4;

Figure 8 is a view showing in rear elevavievvs, withv portions-thereof broken away;

Figure 9 is a fragmentary View taken substantially on the line 9-9 of Figure 6, with the bridgingplates removed;

Figure 10 is a vertical sectional view taken on the line 10-10 of Figure 5;.

Figure 11 is a sectional view taken on the line 11-11 of Figure 3;

Figure 12 is, a. horizontal sectional view taken on the line 12-12 of Figure 8; i(

Figure 13 is a view similar to Figure 9, with the bridging plates in position;

Figure 14 is a vertical sectional -view taken on the line 14-14of4Figure 12.

Similar reference characters refer to similar parts in each of the several views.

Referring specifically to the drawings, and particularly to Figuresfl and 12, the furnace embodying my invention comprises a combustion chamber C defined by an up# per wall 15, side walls 16, a front end wall 17 and a vbottom wall 18. The several walls comprising the combustion chamber are made of suitable refractory material, the bottom wall 18 bein-g made of fire-brick supported upon angle bars 19 arranged in bridging relation to a metallic supporting frame including angle bars 20 supported upon leg irons 21 and held in spaced relation to main angle bars 22 of the metallic frame. The inner end of the bottom'wall 18 abuts the vertical wall 23 which is a continuation of the ioor'24 of the fire-bricks of the boiler shown in Figure 1.

The front ,end vwall 17 connects the top and' bottom walls 15 and 18 and, as shown,

- maybe admitted to the combustion cham er C. A ,Suitable refractory. material 29 is arranged in surrounding relation to the pipes 28 and between the pipes and plates 30 and 31. "The lower plate 30 is secured to the lower angle bar 26, lwhile the upper plate 31 u is secured between the upper angle bar 26 purpose of reinforcing the rods in any position. The rods 51 may4 vand an angle bar 32. The bar 32 serves to supportvthe outer ends of a plurality of T- beams 33 which are designed to sup ort firebricks 34, which latter constitute t e upper wall 15 of the combustion chamber. As clearly shown in Figures 5 and 7, the T- beams 33 are inverted and arranged at regular intervals, and the {ire-bricks 34 fare formed with T-shaped grooves .34'a which permits the bricks to be slid on to the beams and thus supported by the latter, as will be understood. This manner of associating the bricks with-the beams permits of the ready assembling and disassembling of the upper wall of the combustion chamber and thus facilitates substitution of the fire-bricks should they become cracked or broken.

The T-beams 33 are supported at their rear ends by means of brackets 35 riveted to the beams and having laterally extending lips 36 which rest upon a relatively large angle bar 37 which is secured at its opposite ends to vertically disposed channel bars 38 (Figure 12). These brackets 35 also serve to support vfire-brick l39 which constitutes an upper'extension of the .upper wall 15 to span the space between the upper wall and the hre-bricks 40 constituting the boiler setting. The fire-bricks 40 are supported upon angle bars 41 and a centrally dlsposed T- beam 42., as clearly shown in Figure 4. These bars and beams 41 and 42 are in turn supported upon the uppermost angle bars 43 of the main metallic frame and to which the bars or upper ends of the bars 27 and 38 are connected.

vSpanning the bars bars 41 are channel bars 43 in advance of the 44 designed for the the main metallic frame and supporting a cover plate 45 thereon. The front or outer ends of the bars 43 are connected to vertical bars 46, as clearly shown in Figure 4, and detachably secured to these bars is a front cover plate 47 provided with openings 48 c ontrolled by doors 4 9 mounted for sliding movement in guides 50 and capable of-being secured in any adjusted position b means of rods 51 eX- tending through rackets 52, which latter are provided with set screws 53 for securing be graduated as shown, so that the positions of the several doors 'can be readily determined and made uniform. In the present instance I have shown four openings 48 and one door 49 for each of the openings. These openings are arranged in pairs, the openings of each pair being disposed one above the other and separated from each other by means of a channel bar 54, the bar being common to both pairs of openings.

To provide recurrent passages between the walls of the combustion chamber C and the c'over plates 454and 47 through which air may be caused to circulate completely 57, such baffles being arranged substantially midway between the walls of the combustion chamberand the cover plates 45 and 47..

on angle barsv The upper baiiie is supported 58, the lower baille on angle bars 59 and the front late securedto one of the bars 58 and one of the bars 59 in the manner clearly shown in Figure 4. The front baiiie completely spans the space between the upper and lower baffles and 56, while the latter terminate short ofthe brickworkat the end of the combustion chamber, and for. the purpose of allowing the circulation of air around to the 4inner sides of the bailies, as indicated `by the arrows in Figure 4.

From the foregoing arrangement of baiiles it will be clear that they co-operate with the walls of the combustion chamber and the cover plates to form a. vertical passageway 60 and two horizontal passageways 61 in communication with the vertical passageway at one end and with other horizontal passageways 62. Between the front wall of vthe combustion chamber vand l'the baffle 57 another vertical passage 63 is formed, which is in communication with the several pipes..

28. The vertical passage 60 is adapted to have air supplied thereto through the openings 48, and when the furnace is in operation air will, be supplied to and circulate through the se veral passages in the manner indicated by the arrows in Figure 4, the air ultimately reaching the-combustion chamberA through the pipes 28.

As previously stated, my furnace is adapted for both oil and gas burners, and in the present instance I have shown a multiplicity of gas burners 64 arranged in groups of three, with the burners of each group disposed one above the other and adjacent the corresponding set of pipes 28. Of course it will be understood that the number and arrangement of the pipes and gas burners is arbitrary and may be varied to suit a particular boiler. However, I have found that arranging the burners in groups and superposing the burners of each group, facilitates uniform application and distribution of heat to and about the boiler.

As clearly shown in Figure 12, the groups of gas burners 64 are arranged one beside the other land transversely of the furnace. However', for the purpose of accommodating an oil burner 65 one set of gas burners has been omitted at a point centrally .of the furnace. In Figure. 2L I have shown three I burners, and without departing from the spirit of my inventipn.

The several gas burners 64 of any one group arein communication with a gas distributing box 66 which latter, as clearly shown in Figure 4, is sustained upon angle bars 67. As shown in Figure 5, the several distributing boxes are arranged in spaced relation to each other for the purpose of providing access to the gas burners through the openings 48. Gas is supplied to the several boxes 66 through branch pipes 68 connected to a gas supply manifold 69 which is connected to any suitable source of gas supply. For the purpose of simultaneously controlling the flow of gas to all of the several distributing boxes l provide in the intake manifold a master valve 70 (Figure 12), and to control the ow of gas to any one distributing box independently of the others, valves 71 are provided in each of the grooves 74 by means of latch lu -to engage or disengage the bri ge. plates to branch pipes 68. The branch pipes extend through suitable openings formed in the channel bar 54 and may be made up of sections,l as shown, to facilitate the application or removal of the pipes to and from the manifold and boxes. Gas entering any one of the distributing boxes is caused to be uniformly distributed to the several burners of that particular group by` means of a. battle plate 72 arranged within the box in the manner shown in Figure 4.

The spaces' between the several distributing boxes 66 are normally spanned by bridging plates 73 which, as shown to advantage in Figures 10 and 13, are retained within 7 5 pivoted allow of the ready application .or removal of such plates. Each plate 73 is provided with two sight openings 76 normally closed by pivoted shutters 77.

As shown in Figure 13, the bridge plate 73 for spanning the space between the two distributing boxes at opposite sides of the oil burner is provided with an opening for accommodating a pipe 78, which, as shown in Figure 6, extends from the front wall of the combustion chamber to the front cover plate 47. This pipe provides an air duct or port for supplying air to the oil burner 65. The

pipes 28 above and below the pipe 78 are still utilized to supply air for two gas burners 64 which are extended laterall adjacent distributing boxesin t e manner clearly shown in Figures 6 and 9. As shown in Figures 2 and 6, a branch pipe 79 is connected to the oil burner 64 and extends to the front of the furnace, where itis connectl ed to an oil supply pipe 80. A valve 81 is provided to control the assage of oil from.

the supply pipe to the urner.I In Figure f?.a I have shown three oil burners 65, each provided with branch pipes 79 connected to -a common` supply pi e 80 and valves 81 at the junction of eac ranch pipe and supply pipe so that the passage of oil to any one from the burner can be controlled independently of the others.

As shown in Figure 3, the front cover plate 47 is provided with an opening to accommodate the pipe 7 8, and in order to Control the passage of air through the pipe a shutter 82l is provided, slidably mounted in the guides 50, and formed with an opening 82a to accommodate the branch pipe 79.

.In the applied position of thel furnace with respect to a boiler such as that shown in Figure l, the inner or open end of the combustion chamber C is in communication with the tire box of the boiler so that the heat emanating from the oil and gas burners, is directed into the lire box. plied to the several distributing boxes 66, the

As gas is supgas emanating from the. burners 64 can be lighted so that ignition or combustion of the gases occurs in the combustion chamber, it being understood that combustion does not take place until the gas has traversed theV pipes 28. As the gas is under pressure the iow of g'as through fthe pipes sets up a. circulation of air through the pipes and into the combustion chamber, which, `in turn, causes drafts of air in the passageways 60 to 63, inclusive, and in the direction -of the arrows. After continued operation of the furnace the {ire-brick becomes heatedto a high degree. The heat is radiated outwardlyu from the tire-brick into the passageways 62 and 63, and with air constantly circulating through these passageways it will be clear that air from the atmosphere, before actually entering the combustion chamber, absorbs this radiated heat which is ordinarily lost, and thus becomes preheated be. fore entering the pipes 28. With the in'- troduction of preheated air into the pipes, together with the gas emanating from the burners 64, it will be clear that the gas-is converted into a highly combustible mixture. It will be noted that the passageways completely surround the combustion chamber sothat all the heat radiated from the fire-brick and refractory material is utilized to. preheat the air whichis combined with the gas. It has been found, in practice, that air circulating in passageways prevents radiation of heat beyond the bailies 55, 56, etc. to such an extent that the hand may be placed upon the cover platesI 45 and 47. This is of great advantage because a relatively low temperature may be maintained in the boiler room during the operation of the furnace. Further, circulation of Iair. through the assageways maintains the front part of the operator may. shut down and -repair any one group of gas burnerswhile the other groups ,continue to operate. I i

The iow of air through the passageways can be readily controlled through the medum of the doors49, and when thel oil burnrnace relatively cool so that an er 65 is in operationVV the How of air through the pipe 78 can be controlled by the shutter 82. The How of gasto thel several groups of burners can be simultaneously controlled by the master valve 70, but an individual control is also provided through the medium of the valves 71 in the branch pipes 68. It will thus be seen that any one group of gas burners can be controlled at will independentl of the other groups of burners so that the urners in operation and the Haines ema- Vnating from the burners can be positively controlled to suit the individual characteristics of any particular boiler. For example, if the natural drafts of a boiler are such as to interfere with the distribution of the heat to the central portion of the boiler, this diiiculty may be overcome by i-ncreasing the flow of gas from the burners arranged centrally of the furnace and decreasing the flow of gas from the burners at the sides ofthe furnace.

From a consideration of Figure 2 it will be manifest that the several oil burners G5 lform double air chambers at allsides of the combustion chamber ,through which airadmitted through the air ports is caused to describe recurrent paths at each side of the combustion chamber and to finally enter the combustion chamber.

2. A furnace having -a combustionlchamr ber provided -in its front Wall with open ended pipes leading to said combustion chamber, burners opening into the respective pipes at the front ends thereof, an enclosure partly encasing the combustion chamber and provided with spaced-apart walls in front of the combustion chamber andspaced-apart Walls respectively above and below the combustion chamber, therespective walls of the sinuous course terminating'at the said pipes and around said burners, and means for .admitting regulating volumes of air to the course defined by the walls of said enclosure so that vair in relatively separated lanes travels continuously at points in front and at the top and bottom of the combustion chamber, thereby'subjccting the vair to the action of heat radiating from the walls of thecombustion chamber to preheat said air before same reaches said burners andto utilize the action of the incoming air directly in front of the combustion chamber as a heat insu- 'lator to maintain the front Wall of the enclosure in a relatively chilled state.

3. A furnace havin `r a combustionl chamber provided in its front wall with open ended pipesleading to said combustlon chamber, burners opening into the respective pipes at the front ends thereof, an enclosure partly encasing the combustion chamber and provided with spaced-apart walls in front of the combustion chamber and spaced-apart walls respectively above and below the combustion chamber, the respect-ive Walls of the enclosureco-acting relatively to provide a sinuous'course terminating at the said pipes and around said burners, and means for admitting regulated volumes of air to the course defined by the walls of said enclosure so that air in vrelatively separated lanes travels continuouslyat points in frontend at the top and bottom ofthe combustion chamber, thereby subjecting the .air to the action of heat radiating Yfrom the walls of the combustion chamber to preheat said air .before same reaches said burners and to utilize the action of the incoming air directly in front of the combustion chamber as a heat insulator to maintain thev front Wall of the enclosure in a relatively chilled state, fuel distributing boxeslocated in the enclosure, the burners extending fromlsaid boxes, and means for delivering fuel to said boxes,.the said 'boxes Aalso disposed with respect to the combustion chamber so as to be subjected to the effect of the heat of the combustion chamber and theaction of the preheated mixing air as the latter proceeds to said pipes.

HERBERT V. LEAHY.

enclosure co-acting relatively to provide a 

